The present invention relates to improved float valves and more particularly to float valves of the type including a regulating pilot valve which is operated by a float responsive to the level of water or other liquid supplied by the valve.
Such a float valve is disclosed in my earlier U.S. Pat. No. 4,013,091 entitled FLOAT-CONTROLLED VALVE, issued Mar. 22, 1977, which patent is hereby incorporated into the present disclosure by reference. A similar float valve is also disclosed by my still earlier U.S. Pat. No. 3,893,475 entitled FLOAT VALVE, issued July 8, 1975.
A float valve of the type disclosed by each of the above-noted patents includes a valve casing having an upper supply port controlled by a main valve member. A diaphragm carrying the main valve member cooperates with a bottom wall of the casing to form a control chamber. Increasing pressure in the control chamber causes the main valve member to close against the supply port while decreasing pressure causes the main valve member to retract into an open position. Water pressure is preferably supplied to the control chamber through a small conduit means in the form of an upright tube carried by the main valve member and extending upwardly through the supply port.
In order to control opening and closing of the supply port by the main valve member, pressure within the control chamber is regulated by a bleeder port formed in a fixed bottom wall of the valve casing, the bleeder port being opened and closed by means of a small upright pilot valve member mounted upon the upper side of a float element. The pilot valve member is preferably a simple pin which cooperates with a valve seat in the form of a small O-ring held in place by suitable retainer means.
A valve of the type summarized above and disclosed by the above-noted references performs very satisfactorily in regulating the liquid level in a vessel supplied from the supply port. Such a float valve has been found to be particularly rugged and capable of trouble-free operation over extended periods of time.
However, in order to even further improve operation of such float valves, it has been found desirable to stabilize operation of the float valve by reducing sensitivity to momentary fluctuations in water level produced for example by small ripples or waves in a liquid which controls the float valve. This need was partially met by my second U.S. Pat. No. 4,013,091 wherein water from the bleeder port was discharged into an expansile chamber, the outlet of which was sufficiently restricted in order to further depress the float during valve actuation in order to increase the volume of water released during each float cycle. However, this feature does not effect response of the float to minor surface variations when the water level has dropped toward a point at which the valve is designed to open or be actuated.